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Tytuł:
Determination of adsorption isotherm models for the biosorption of chromium using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/11799.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
determination
adsorption isotherm model
biosorption
chromium
cherry
leaf
Muntingia calabura
Opis:
Contaminations of industrial metals into the river possess major threat to environment. Chromium is a heavy metal which has the wide applications in tannery and electroplating industries. Above the permitted level of Chromium(VI) into surface water leads to severe health hazards. Therefore, biosorption is a technology used for the sorption of heavy metal. In this present study adsorption isotherm models was studied for the biosorption of chromium by cherry leaves. From the adsorption isotherms it was found that the experimental data fits well with the Langmuir isotherm than the Freundlich isotherm. The monolayer capacity Qm was fond to be 11.98 mg/l and the adsorption affinity was found to be positive which indicates the efficient biosorption of chromium.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of thermodynamic properties for the biosorption of chromium by using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/11897.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
thermodynamic property
biosorption
chromium
cherry
leaf
Muntingia calabura
entropy
Opis:
Chromium is a heavy metal which has widely used in tannery and electroplating industries. Contaminations of these industrial metals into the river possess major threat to an environment. Therefore, biosorption is a technique which is applied for the sorption of heavy metal by a biomaterial. In the present study reveals that cherry leaves was used as a biomaterial and for that the thermodynamic properties was evaluated for the biosorption of chromium. From the thermodynamic studies it was found that the reaction was feasible, spontaneous and exothermic because the values of ΔG = negative, ΔS = negative and ΔH = positive. So, it was concluded that the experiment was thermodynamically feasible.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic studies for the biosorption of chromium using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/10873.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
kinetics
biosorption
chromium
cherry
leaf
Muntingia calabura
Opis:
Biosorption is an attractive technology which is used for the sorption of substances by a biomaterial. In this present work the heavy metal chromium was subjected to biosorption because of their non-degradability nature and causes water and land pollution. Cherry leaves were used as a biomaterial for the biosorption. Kinetic studies were performed for the biosorption experiment. From the experiment it was found that the reaction follows pseudo first order reaction because of the larger value of regression coefficient R2 and lower value of standard errors (χ2) for pseudo first order reaction than second order reaction.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of chromium by biosorption method (chitosan)
Autorzy:
Abatneh, Y.
Sahu, O.
Powiązania:
https://bibliotekanauki.pl/articles/11428.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
removal
chromium
biosorption
chitosan
absorbent
polymer
water
rheological measurement
Opis:
Discharge of metal containing effluents into water has been a cause of major concern. Traditional treatment methods are proving to be ineffective and expensive. Chitosan was studied as a potential biosorbent due to its positive charge and relatively low cost. The study involves evaluating the metal binding performance of chitosan in a Polymer Enhanced Diafiltration (PEDF) system which uses an ultra filtration membrane to retain the chitosan which, in turn, binds the metal, thereby preventing passage into the permeate stream. Conditions for binding such as pH, concentration of polymer and chromium were studied. Optimal performance was obtained when the system was operated at pH values lower than the pKa of chitosan i.e. 6.3. Using 6 g/L chitosan at pH 4.0, chromium concentration was reduced to less than 1mg/L from a feed concentration of 20 mg/L. Equilibrium dialysis experiments were done to study the kinetics of binding and the uptake of metal per gram of polymer. Rheological measurements demonstrated that in the presence of 1-100 mM chromate, chitosan was found to be slightly shear thickening at low concentrations such as 4 g/L and 6 g/L whereas it was slightly shear thinning at higher concentrations like 12 g/L and 20 g/L This suggests that neutralization of chromium anions is due to the interaction of multiple chitosan molecules. This result is consistent with the relatively stiff nature of the polysaccharide. Overall, this study suggests that some modification of the native polymer would be required to improve uptake and make it an industrially workable process.
Źródło:
International Letters of Natural Sciences; 2014, 03
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of Hexavalent Chromium from Aqueous Solution by the Pod of Acacia gerrardii
Autorzy:
Abdulaziz, Mohammed A.
Bakri, Abdulrahman A.
Al-Zahrani, Saleh A.
Al-Zahrani, Majed S.
Al-Lehebi, Abdulrahman N.
Banjar, Fadil M.
Nabag, Mohand I.
Powiązania:
https://bibliotekanauki.pl/articles/779613.pdf
Data publikacji:
2019
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Biosorption
chromium
Acacia gerrardii
isotherm models
Park kinetic models
Opis:
This study aims at investigating the potential of Acacia gerrardii pod for the removal of Cr(VI) in batch system. Effect of solution pH, biosorbent dosage, initial concentration of Cr(VI), contact time on the removal process was examined. Complete removal of hexavalent chromium was achieved at pH values 1.0 and 2.0 whereas maximum removal of total chromium was obtained at pH of 3.0. The study showed that the biosorption and bioreduction mechanisms were involved in the removal process. The time required for complete removal of Cr(VI) using the pod of Acacia gerrardii was shortened with an increase in biomaterial dosage and decrease in Cr(VI) concentration. Kinetic data was well described using Park kinetic model. Freundlich isotherm model adequately fitted the equilibrium data indication multilayer adsorption of total chromium on the surface of biomaterial. The pod of Acacia gerrardii could be used efficiently for the removal of hexavalent chromium from aqueous solutions.
Źródło:
Polish Journal of Chemical Technology; 2019, 21, 2; 14-19
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of Total Chromium Levels from Raw Tannery Wastewater via Electrocoagulation using Response Surface Methodology
Autorzy:
Aguilar-Ascón, Edwar
Marrufo-Saldaña, Liliana
Neyra-Ascón, Walter
Powiązania:
https://bibliotekanauki.pl/articles/124384.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
chromium
electrocoagulation
tannery wastewater
aluminum electrodes
response surface
Opis:
This study focused on reducing total chromium levels in raw wastewater from the leather tanning industry via electrocoagulation to comply with maximum permissible limits (MPL) and to determine the effects of main process parameters. An electrocoagulation reactor was built using aluminum electrodes as an anode and cathode. Then, the response surface methodology was applied using a 3k factorial design considering three factors, namely current intensity, treatment time, and pH. The total chromium removal percentage was considered as a response variable. 99% of the total chromium found in wastewater could be removed after 14-min treatment at 2-A current intensity and pH 5.5. Similar amount of chromium was removed at pH of 8.5 and 7. Statistical analysis performed at a confidence level of p < 0.05 revealed that all three factors influenced electrocoagulation. Total chromium could be efficiently removed from raw wastewater at a current intensity of 2.9 A, a pH of 8.4, and a treatment time of 21 min, suggesting that electrocoagulation using aluminum electrodes is an efficient method for total chromium removal. Thus, this process must be considered as a solution to the problems caused by the leather tanning industry and for better compliance with the MPL established in the Peruvian environmental standards.
Źródło:
Journal of Ecological Engineering; 2019, 20, 11; 217-224
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytoextraction of Cr by maize (Zea mays L.) : the role of plant growth promoting endophyte and citric acid under polluted soil
Autorzy:
Ali, J.
Mahmood, T.
Hayat, K.
Afridi, M. S.
Ali, F.
Chaudhary, H. J.
Powiązania:
https://bibliotekanauki.pl/articles/204568.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
maize
phytoextraction
chromium
citric acid
Burkholderia vietnamiensis
Opis:
High chromium (Cr) toxicity has turned into a serious environmental concern. Cr contaminated agronomic soils negatively affect the growth and yield of crops. Current research was conducted to enhance the phytoextraction potential of maize by using Burkholderia vietnamiensis and citric acid (CA). Plants were subjected to three concentrations of Cr (0.86, 350, and 500 ppm). A pot experiment was conducted under greenhouse conditions with completely randomized design (CRD). After 72 days of experiment, plants were harvested to analyze the morphological and biochemical attributes of soil, bacteria and plant. Results revealed that plant fresh, dry biomass, root, shoot length and chlorophyll contents significantly increased by 56%, 50%, 58%, 78% and 60%, respectively, at 500 ppm Cr concentration in combine treatment of B. vietnamiensis and CA. Maize plants treated with both B. vietnamiensis and CA significantly increased the bioaccumulation (BA) of Cr up to 50% and translocation factor (TF) by 31%. Furthermore, superoxide dismutase (SOD), proline and peroxidase dismutase (POD) activities in leaves were markedly increased by 30%, 42% and 15%, respectively, when treated with CA. Current study reveals that exogenous co-application of B. vietnamiensis + CA enhance plant growth by alleviating heavy metal stress and accelerate the phytoextraction of Cr. Taking into account the heavy metal tolerance and accumulation capacity, Zea mays is suitable for phytoremediation of contaminated soils in combination with B. vietnamiensis and CA.
Źródło:
Archives of Environmental Protection; 2018, 44, 2; 73-82
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Capping Treatment of Copper and Chromium Contaminated Sediment with Bentonite Kaolin and Sand to Inhibit their Release to the Overlying Water
Autorzy:
Aliyu, Mohammed Kabir
Abd Karim, Ahmad Tarmizi Bn
Chan, Chee Ming
Abdulkadir, Aeslina
Bin Daud, Zawawi
Oyekanmi, Adeleke Abdulrahman
Powiązania:
https://bibliotekanauki.pl/articles/2202312.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
in situ capping
polluted sediment
bentonite
kaolin
chromium
copper
Opis:
The public concern over sediment contamination brought on by mining operations, excessive use of chemical fertilisers or pesticides, industrial, agricultural, and municipal effluent, is increasing. Dredging is a more expensive treatment option than in situ capping of polluted sediment for immobilising pollutants in sediments on site. In order to stop the release of Cr and Cu from chemically contaminated sediments, this study aimed to evaluate the efficiency of utilising active capping materials such as bentonite (B), kaolin (K), and a 1:1 combination of bentonite and kaolin (BK) as capping materials. In a 90-day laboratory experiment carried out in glass tanks with a 1 cm thickness cover of capped material plus sand spread over the polluted sediment, the efficacy of B, K, and BK in inhibiting trace metal leachability was examined. The findings demonstrated that B and BK decreased the ability of sediments to leach Cr and Cu. The results suggest that BK and B should be considered as a suitable active material for capping treatment of polluted sediment sites because of their high Cu and Cr trapping. According to an analysis of adsorption kinetics, chemisorption was the adsorption process. The outcomes of this study demonstrated the potential for using kaolin, a bentonite-kaolin clay mixture covered with sand, and bentonite as capping materials for the in-situ treatment of Cr and Cu polluted coastal sediments.
Źródło:
Journal of Ecological Engineering; 2022, 23, 12; 264--272
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hot Dipping of Chromium Low-alloyed Steel in Al and Al-Si Eutectic Molten Baths
Autorzy:
Attia, G. M.
Afify, W. M. A.
Ammar, M. I.
Powiązania:
https://bibliotekanauki.pl/articles/1837860.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coating
hot dipping
aluminizing
chromium low alloyed steel
powłoka
aluminiowanie
stal niskostopowa chromowa
Opis:
Chromium low alloyed steel substrate was subjected to aluminizing by hot dipping in pure aluminium and Al-Si eutectic alloy at 750°C and 650°C respectively, for dipping time up to 45 minutes. The coated samples were subjected for investigation using an optical microscope, scanning electron microscopy (SEM), Energy-dispersive X-ray analyzer (EDX) and X-ray diffraction (XRD) technique. Cyclic thermal oxidation test was carried out at 500°C for 72 hours to study the oxidation behaviour of hot-dipped aluminized steel. Electrochemical corrosion behavior was conducted in 3wt. %NaCl aqueous solution at room temperature. The cyclic thermal oxidation resistance was highly improved for both coating systems because of the formation of a thin protective oxide film in the outermost coating layer. The gain in weight was decreased by 24 times. The corrosion rate was decreased from 0.11 mmpy for uncoated specimen to be 2.9 x10-3 mmpy for Aluminum coated steel and 5.7x 10-3 mmpy for Al-Si eutectic coated specimens. The presence of silicon in hot dipping molten bath inhabit the growth of coating intermetallic layers, decrease the total coating thickness and change the interface boundaries from tongue like shape to be more regular with flatter interface. Two distinct coating layers were observed after hot dipping aluminizing in Al bath, while three distinct layers were observed after hot dipping in Al-Si molten bath.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 30-50
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hot Dipping of Chromium Low-alloyed Steel in Al and Al-Si Eutectic Molten Baths
Autorzy:
Attia, G. M.
Afify, W. M. A.
Ammar, M. I.
Powiązania:
https://bibliotekanauki.pl/articles/1837787.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coating
hot dipping
aluminizing
chromium low alloyed steel
powłoka
aluminiowanie
stal niskostopowa chromowa
Opis:
Chromium low alloyed steel substrate was subjected to aluminizing by hot dipping in pure aluminium and Al-Si eutectic alloy at 750°C and 650°C respectively, for dipping time up to 45 minutes. The coated samples were subjected for investigation using an optical microscope, scanning electron microscopy (SEM), Energy-dispersive X-ray analyzer (EDX) and X-ray diffraction (XRD) technique. Cyclic thermal oxidation test was carried out at 500°C for 72 hours to study the oxidation behaviour of hot-dipped aluminized steel. Electrochemical corrosion behavior was conducted in 3wt. %NaCl aqueous solution at room temperature. The cyclic thermal oxidation resistance was highly improved for both coating systems because of the formation of a thin protective oxide film in the outermost coating layer. The gain in weight was decreased by 24 times. The corrosion rate was decreased from 0.11 mmpy for uncoated specimen to be 2.9 x10-3 mmpy for Aluminum coated steel and 5.7x 10-3 mmpy for Al-Si eutectic coated specimens. The presence of silicon in hot dipping molten bath inhabit the growth of coating intermetallic layers, decrease the total coating thickness and change the interface boundaries from tongue like shape to be more regular with flatter interface. Two distinct coating layers were observed after hot dipping aluminizing in Al bath, while three distinct layers were observed after hot dipping in Al-Si molten bath.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 37-50
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biosorption of Heavy Metals from Synthetic Wastewater by Using Macro Algae Collected from Iraqi Marshlands
Autorzy:
Bahaa, Shaymaa
Al-Baldawi, Israa Abdulwahab
Yaseen, Safaa Rasheed
Abdullah, Siti Rozaimah Sheikh
Powiązania:
https://bibliotekanauki.pl/articles/123810.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
adsorption
Cladophora
copper
cadmium
chromium
aqueous solutions
Opis:
Biosorption is fast, effective and low cost process. It takes place in a wide range of temperature and it can be used for almost all types of heavy metals. The aim of this study was to investigate the ability of locally collected green macro algae to remove copper, chromium and cadmium from synthetic wastewater. The fresh algae were converted into dry powder as biosorbent. In the investigations, 1 g of macro algae powder was exposed to synthetic waste water contaminated with 10 mg/L concentration of copper, chromium and cadmium in separate exposure for 2 hours. The best removal efficiency for copper, chromium and cadmium were 70%, 80% and 85%, respectively, from the initial concentration of 10 mg/L. While macro algae are abundantly available in marshlands of south Iraq, it can be preferably utilized as biosorbent to remove heavy metals from the industrial wastewater.
Źródło:
Journal of Ecological Engineering; 2019, 20, 11; 18-22
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromium toxicity in Sesbania sesban (L.) Merr
Autorzy:
Bakiyaraj, R.
Mahakavi, T.
Baskaran, L.
Powiązania:
https://bibliotekanauki.pl/articles/10775.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
chromium
toxicity
Sesbania grandiflora
pot experiment
toxic effect
plant
germination
chlorophyll
enzyme
metal accumulation
seedling
shoot
Opis:
Chromium is one of the most common toxic metals present in the environment that induces various toxic effects in plants. A pot experiment was conducted to determine the effects of chromium on germination percentage, seedling growth, chlorophyll ‘a’, ‘b’ and proline content of Sesbania sesban (L.) Merr. The seedlings were treated with different concentrations of control, 0.10, 0.25, 0.50, 0.75 and 1.00 g kg-1 of chromium. The parameters such as germination percentage, root and shoot length, seedling fresh weight dry weight, chlorophyll ‘a’, ‘b’ and proline content of leaves were measured. Our results indicated that a significant inhibitory effect was observed at all levels of chromium compared to control. Increasing the concentration of chromium to 1.00 g kg-1 showed a significant decrease in seed germination, shoot and root length, fresh weight, dry weight and chlorophyll ‘a’ and ‘b’ content of plant. While proline, catalase and peroxidase contents were increased by increasing Cr concentration. It was also noted that accumulation of chromium in the roots was much higher than the shoots of the seedlings under treatment.
Źródło:
International Letters of Natural Sciences; 2014, 04
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lead, Nickel and Chromium Content in Grass on Land Reclaimed by Sewage Sludge and Mineral Wool Grodan Application
Zawartość ołowiu, niklu i chromu w trawie uprawianej na gruncie rekultywowanym przy wykorzystaniu osadu ściekowego i wełny mineralnej Grodan
Autorzy:
Baran, S.
Wójcikowska-Kapusta, A.
Żukowska, G.
Makuch, I.
Powiązania:
https://bibliotekanauki.pl/articles/387767.pdf
Data publikacji:
2010
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
rekultywacja
ołów
nikiel
chrom
trawa
grunt
osad ściekowy
wełna mineralna
reclamation
lead
nickel
chromium
grass
ground
sewage sludge
mineral wool
Opis:
The objective of the present research was to analyze the impact of sewage sludge and post-use mineral wool applied to reclaim the devastated heavily acidified land, on heavy metal content in land reclamation grass seed mixture. The work presents the research findings from the three-year study period. There was analyzed grass obtained from the lst cut as well as soil samples from 0-20 cm depth. The experiment was set up on the post-sulfur mining land in Jeziorko. The 5 are-plots underwent the deacidification treatment with post-flotation lime followed by the employment of differentiated mineral wool doses (200, 400 and 800 m3 o ha-1) along with a sewage sludge-amended dose. Ground in all the reclamation variants was characterized by a Iow content of lead, chromium and nickel. A grass mixture from all the planting dates showed a natural level of the aforementioned trace elements. A grass Cr and Ni content was shown to be unaffected by sewage sludge and post-use mineral wool use for reclamation purposes. Mineral wool supplement implicated a proportional increase of a grass lead content.
Celem niniejszych badań była analiza wpływu osadu ściekowego i poużytkowej wełny mineralnej, zastosowanych do rekultywacji zdewastowanego przez silne zakwaszenie gruntu, na zawartość metali ciężkich w rekultywacyjnej mieszance traw. W pracy przedstawiono wyniki z trzech lat badań. Analizowano trawę z pierwszego pokosu, jak również glebę pobraną z głębokości 0-20 cm. Doświadczenie założono na terenie byłej kopalni siarki w Jeziorku. Na poletkach o powierzchni 5 arów, po wcześniejszym odkwaszeniu wapnem poflotacyjnym, stosowano zróżnicowane dawki wełny mineralnej (200, 400 i 800 m3 o ha-1), na tle melioracyjnej dawki osadu ściekowego. Rekultywowany grunt we wszystkich kombinacjach nawozowych charakteryzował się małą zawartością ołowiu, chromu i niklu. W mieszance traw ze wszystkich pokosów stwierdzono naturalną zawartość omawianych metali ciężkich. Zastosowane do rekultywacji osady ściekowe i poużytkowa wełna mineralna nie miały wpływu na zawartość w niej chromu i niklu. Wzrastające dodatki wełny mineralnej zwiększały proporcjonalnie zawartość ołowiu w trawie.
Źródło:
Ecological Chemistry and Engineering. A; 2010, 17, 4-5; 377-383
1898-6188
2084-4530
Pojawia się w:
Ecological Chemistry and Engineering. A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser surface modification of borochromizing C45 steel
Laserowa modyfikacja borochromowanej stali C45
Autorzy:
Bartkowska, A.
Pertek, A.
Jankowiak, M.
Jóźwiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/354502.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chromowanie
stal borochromowana
laserowa obróbka cieplna
mikrostruktura
mikrotwardość
chromium plating
diffusion boriding
laser heat treatment
microstructure
microhardness
Opis:
n this study the test results for borochromized C45 steel after laser surface modification were presented. Influence of laser heat treatment on the microstructure and microhardness of surface layer was investigated. The process of borochromizing consisted of chromium plating followed by diffusion boronizing. The laser heat treatment (LHT) of multiple tracks in the helical line was carried out with CO2 laser beam. The technological laser TRUMPF TLF 2600 Turbo CO2 of the nominal power 2.6 kW was applied. Borochromizing was carried out with laser power density q = 41.40 kW/cm2 and at laser beam scanning rate v = 0.67 m/min and v = 2.016 m/min. Measurements of microhardness were conducted using the Vickers' method and Zwick 3212 B hardness tester. Microstructure observations were performed by means of an optical microscope Metaval Carl Zeiss Jena and scanning electron microscope Tescan VEGA 5135. After laser heat treatment with re-melting a three-zone layer was obtained, which included: re-melted zone, heat affected zone and a core. Influence of laser treatment parameters on thickness of melted zone and microstructure of the surface layer was tested. The microhardness tested along the axis of track of the surface layer after laser modification was about 800-850 HV. The results of tests showed influence of laser power density and scanning rate on microstructure and properties of borochromized layers.
W pracy przedstawiono wyniki badań borochromowanej stali C45 po laserowej modyfikacji. Badano wpływ laserowej obróbki cieplnej na mikrostrukturę i mikrotwardość warstwy wierzchniej. Proces borochromowania składał się z obróbki galwanicznej, następnie dyfuzyjnego borowania. Laserowa obróbka cieplna dla ścieżek wielokrotnych po linii śrubowej była wykonana przy użyciu lasera technologicznego CO2 firmy TRUMPF TLF 2600 Turbo o mocy nominalnej 2,6 kW. Borochromowanie przeprowadzono przy użyciu gęstości mocy lasera q = 41,40 kW/cm2 i prędkości skanowania wiązki laserowej v = 0,67 m/min oraz v = 2,016 m/min. Pomiar mikrotwardości wykonano metodą Vickersa na twardościomierzu Zwick 3212B. Natomiast badania mikrostruktury przeprowadzono przy użyciu mikroskopu Metaval produkcji Carl Zeiss Jena jak również skaningowego mikroskopu elektronowego Tescan VEGA 5135. Po laserowej obróbce cieplnej z przetopieniem otrzymana warstwa składała się z trzech stref: przetopionej, wpływu ciepła i rdzenia. Badano wpływ parametrów laserowej obróbki na grubość i mikrostrukturę strefy przetopionej. Mikrotwardość w osi ścieżki warstwy wierzchniej po laserowej modyfikacji wynosiła ok. 800-850 HV. Wyniki badań wykazały wpływ oddziaływania gęstości mocy lasera i prędkości posuwu na mikrostrukturę oraz właściwości warstw borochromowanych.
Źródło:
Archives of Metallurgy and Materials; 2012, 57, 1; 211-214
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Wear Mechanism of High-Chromium Gyratory Crusher Mantle Lining in Terms of the Assessment of the Used Material
Analiza zużycia stożka wewnętrznego kruszarki stożkowej pod kątem oceny zastosowanego materiału
Autorzy:
Bembenek, Michał
Krawczyk, Janusz
Zagórski, Krzysztof
Pawlik, Jan
Powiązania:
https://bibliotekanauki.pl/articles/27310181.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
gyratory crusher
erosion wear mechanism
high-chromium cast steel
kruszarki stożkowe
mechanizm zużycia erozyjnego
staliwo wysokochromowe
Opis:
After the rock is excavated in bulky chunks, it must be processed into fractions usable by diverse branches of industry. There are many approaches to achieving a fine aggregate, and the gyratory crusher is often preferable. Alas, since its working surfaces are subjected to heavy loads of abrasive material, the lining of the gyratory crusher is prone to specific geometry degeneration mechanisms. The authors subjected the mantle lining to a series of tests, such as metallurgical microstructure analysis, chemical composition and hardness evaluation and X-ray examination. Although most mantles are manufactured from the high-manganese Hadfield steel family, the lining was fabricated from high-chromium hypoeutectic white cast steel with a white iron structure. The difference in the chosen material's chemical composition resulted in an uncommon wear mechanism with visible inclined craters emerging in the lower part of the cone, where erosive, dynamically-moving particles were concentrated.
Po wydobyciu skały w dużych kawałkach wymaga ona przetworzenia na frakcje nadające się do wykorzystania przez różne gałęzie przemysłu. Istnieje wiele sposobów na uzyskanie drobnego kruszywa, a kruszarka stożkowa jest często preferowaną opcją. Niestety, jej powierzchnie robocze poddawane są dużym obciążeniom ściernym, co skutkuje tym, że wykładzina kruszarki stożkowej jest podatna na specyficzne mechanizmy degeneracji geometrii. Autorzy poddali wyłożenie stożka szeregowi badań, m.in. analizie mikrostruktury, ocenie składu chemicznego, rentgenowskiej analizie fazowej i twardości w odniesieniu do właściwości tribologicznych na podstawie analizy mechanizmu zużycia. Większość stożków jest wykonywana ze stali wysokomanganowej rodziny Hadfielda, w tym przypadku wyłożenie zostało wykonane z wysokochromowej, podeutektycznego staliwa o strukturze odpowiadającej żeliwu białemu. Zastosowany materiał spowodował występowanie charakterystycznego mechanizmu zużycia w postaci tworzenia się kraterów, gdzie zużycie erozyjne koncentruje się w dolnej części stożka, przy której koncentruje się oddziaływanie większych dynamicznie przemieszczających się cząstek.
Źródło:
Tribologia; 2023, 1; 27--40
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 239

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